At least for unsigned integers i+1!=i, and the only exception to i+1>i is i==UINT_MAX. For signed integers it may be undefined behavior, of course—again in just one instance—but for floating point you may have f+1==f, or (f+1)-f>1 depending on the rounding mode, for many values of f which are nowhere near the limits of the range, not to mention other oddities like (f==f)==false when f is NaN. If you code involves floating-point operations then the number of corner cases you need to test increases greatly.
